The disclosure generally relates to a power factor correction circuit and, more particularly, to a power factor correction circuit of a power converter.
The power utilization efficiency of electronic devices has become more and more important as the energy shortage problem deteriorates. The traditional power converter is typically realized by using diode rectifiers. Although such structure is simple and low cost, serious non-linear distortion occurs at an input current to greatly increase the low frequency harmonics, thereby decreasing the power factor. The power factor is defined as a ratio of the working power to the apparent power, and is an indicator for measuring the power utilization efficiency. Electronic devices with low power factor not only waste energy, but also generate enormous harmonics to adversely affect the stability of the power system and thus cause problems to the power generator, thereby seriously affecting the quality of power supply.
In general, the power factor of the power converter may be improved by adding a power factor correction (PFC) circuit to the power converter. However, the newly developed electronic devices are required to meet more severe total harmonic distortion (THD) requirement, and the structure of traditional PFC circuit is difficult to satisfy the specification requirements of the newly developed electronic devices.